Add multi-threaded tests for acquire/release atomics (#8999)

* Add multi-threaded execution tests exercising acquire/release atomics
* Most tests demonstrate at least one possible result that would not be
possible with `seqcst`. It's impossible to write a test that would fail
on an engine that implements `acqrel` using `seqcst`, since
strengthening an atomic operation is always sound.
* `(atomic.fence acqrel)` currently can't be exercised in a way that's
correct without being completely redundant alongside another acqrel
load/store. With a relaxed memory ordering the test would make more
sense.
* Invoke the pause instruction in the `basic.wast` test which was
previously unexercised
* In support.split_wast, ensure that `(thread ...)` and `(wait ...)`
expressions are captured in the split output (the latter is currently a
no-op anyway but best to include it for readability and correctness).
* Rename relaxed_atomic_execution_tests ->
acquire_release_atomics_execution_tests to match the new proposal name
* Passes in Binaryen's interpreter in an uninteresting way because
`(thread)` blocks always run sequentially in a blocking manner.

Author: stevenfontanella

…s/test/relaxed_atomic_execution_tests.py …quire_release_atomics_execution_tests.pyscripts/test/relaxed_atomic_execution_tests.py renamed to scripts/test/acquire_release_atomics_execution_tests.py scripts/test/relaxed_atomic_execution_tests.py renamed to scripts/test/acquire_release_atomics_execution_tests.py

@@ -80,6 +80,8 @@
   (func (export "i64.atomic.rmw32.cmpxchg_u") (param $addr i32) (param $expected i64) (param $value i64) (result i64) (i64.atomic.rmw32.cmpxchg_u acqrel (local.get $addr) (local.get $expected) (local.get $value)))
 
   (func (export "atomic.fence") (atomic.fence acqrel))
+
+  (func (export "pause") (pause))
 )
 
 ;; *.atomic.load*
@@ -395,6 +397,10 @@
 
 (invoke "atomic.fence")
 
+;; pause
+
+(invoke "pause")
+
 
 ;; unaligned accesses
 

scripts/test/generate_atomic_spec_test.py

@@ -4,7 +4,7 @@
 from dataclasses import dataclass
 from enum import Enum
 
-from relaxed_atomic_execution_tests import acqrel_execution_tests
+from acquire_release_atomics_execution_tests import acqrel_execution_tests
 
 # Workaround for python <3.10, escape characters can't appear in f-strings.
 # Although we require 3.10 in some places, the formatter complains without this.

scripts/test/support.py

@@ -90,7 +90,7 @@ def to_end(j):
             ret += [(chunk, [])]
         elif chunk.startswith('(assert_invalid'):
             continue
-        elif chunk.startswith(('(assert', '(invoke', '(register')) and not ignoring_assertions:
+        elif chunk.startswith(('(assert', '(invoke', '(register', '(thread', '(wait')) and not ignoring_assertions:
             # ret may be empty if there are some asserts before the first
             # module. in that case these are asserts *without* a module, which
             # are valid (they may check something that doesn't refer to a module

test/spec/relaxed-atomics.wast …/spec/acquire-release-atomics/basic.wasttest/spec/relaxed-atomics.wast renamed to test/spec/acquire-release-atomics/basic.wast test/spec/relaxed-atomics.wast renamed to test/spec/acquire-release-atomics/basic.wast

@@ -5348,6 +5348,8 @@
   (func (export "i64.atomic.rmw32.cmpxchg_u") (param $addr i32) (param $expected i64) (param $value i64) (result i64) (i64.atomic.rmw32.cmpxchg_u acqrel (local.get $addr) (local.get $expected) (local.get $value)))
 
   (func (export "atomic.fence") (atomic.fence acqrel))
+
+  (func (export "pause") (pause))
 )
 
 ;; *.atomic.load*
@@ -5663,6 +5665,10 @@
 
 (invoke "atomic.fence")
 
+;; pause
+
+(invoke "pause")
+
 
 ;; unaligned accesses